Convert tasks to new Capistrano 3 format
Load different set of tasks based on Capistrano's version
Compare the release version of Capistrano to accommodate pre-release versions
Check if Capistrano::VERSION is defined

V2 uses Capistrano::Version, not ::VERSION, so this would have thrown
an error when used in V2. (Thanks to @avaranovich for pointing this out)
Add instructions to have Bundler not load the gem by default
Merge pull request #62 from dmarkow/cap3

Capistrano V3 Support
Update README to include Cap v3 info
Update Changelog for upcoming gem release
Use resque_kill_signal setting when killing scheduler.